Is it possible to pre-requisite pact formation? Or is that like a game event and can't be done. For instance, say I create a pact that 2 different races can access and research but then on the formation of the pact it then enables both races to research a new technology.
I was thinking about your mod and if any of this line of thinking would be useful... But to your questions.
Pacts are tricky little beasts (see Manage Pacts Hardcoded?).
The pacts (allianceType) are hardcoded to the existing pact types. You can research the same allianceType in two different races but there are wierd side affects if you form a pact between those two races (see previous link).
This might be close to what you are asking though...
I've tested out a modification that gives PhaseJumpGate technology to TECH and PSI if they form a Phase Drive pact with Vasari. I didn't try linking research for the Phase gate technology for TECH and PSI but I'm assuming it would operate in a similar fashion. It would also be possible to link some new phase technology for Vasari based on the formation of the pact.
Let me know if this is close to what you were thinking. If not, we can try and hash it out further.
Figure 1: shows the pact broken and the technology no longer available.
Figure 2: shows the pact and phase jump gate in action for PSI. That was cool to do